The invention relates to rubber mixtures, to processes for their preparation, and also to their use.
It is known that silanes can be used as coupling agents. For example, aminoalkyltrialkoxysilanes, methacryloxyalkyltrialkoxysilanes, polysulphanalkyltrialkoxysilanes and mercaptoalkyltrialkoxysilanes are used as coupling agents between inorganic materials and organic polymers, as crosslinking agents and as surface-modifying agents.
These coupling agents or bonding agents form bonds with the filler and also with the elastomer and thus bring about good interaction between the filler surface and the elastomer.
It is also known that the use of commercially available silane coupling agents (DE 22 55 577) having three alkoxy substituents on the silicon atom leads to liberation of considerable amounts of alcohol during and after coupling to the filler. Since trimethoxy- and triethoxy-substituted silanes are generally used, considerable amounts of the corresponding alcohols, methanol and ethanol, are liberated.
It is also known that methoxy- and ethoxy-substituted silanes are more reactive than the corresponding long-chain alkoxy-substituted silanes and can therefore couple more rapidly to the filler, and technical and economic reasons have hitherto made it essential to use methoxy and ethoxy substituents.
EP 1285926 discloses organosilicon compounds of the general formulae

where R is a methyl or ethyl group, RI is identical or different and is a C9-C30 branched or unbranched monovalent alkyl or alkenyl group, aryl group, aralkyl group, branched or unbranched C2-C30 alkyl ether group, branched or unbranched C2-C30 alkyl polyether group,
X is NH(3-s), O(C═O)—RIII, SH, S, S(C═O)—RIII or H.
JP 2002145890 moreover discloses compounds of the general formula [[(R1O—)(R2—O—)n]p—R33-pSi—R4]2—Sm.
EP1609516 discloses a process for the extraction of substances from silane-modified fillers. The silanes for modification can be compounds of the formula Z—A—Sx—A—Z.
DE 102005020536.4 and DE 102005020534.8 disclose processes for the preparation of mercaptoorganyl(alkoxysilanes).
A disadvantage of the known rubber mixtures comprising an organo(alkyl polyether silane) is low elongation at break.